Process of modifying ignition temperature, etc., of carbonaceous materials and such materials



Patented Mar. 9, 1926.

UNITED STATES PATENT ot er-cs.

"IRA H. DERBY AND CARLETON B. EDWARDS, or INDIANAPOLIS, INDIANA, ASSIGNORS TO PETER o. REILLY, or INDIANAPOLIS, INDIANA.

rnocnss 0F ODIFYING IGNITION TENDER-Arline, are, or oAnBoNaonoUs MATERIALS AND sUoI-I MATERIALS.

No Drawing.

To all whom it may concern Be it known that We, Ina H. DERBY and CARLIZTON B. EDWARDS, citizens of the United States, residing at Indianapolis, in the county of Marion and State of Indiana, have invented certain new and useful Improvements in Processes of Modifying Ignition Temperature, Etc, of Carbonac eous h fa-terials and Such Materials, of which the following is a specification.

Our invention relates to the manufacture of carbon compositions having relatively lOW ignition temperatures and high burning rates. More specifically, our invention relates to the utilization of metals or metal compounds to modify the ignition temperature and the burning rate of carbonized carbonaceous materials.

Carbonized carbonaceous substances such as petroleum coke, coal-tar coke, gas coke, and the like require heating to comparatively high temperatures to start combustion and their rates of burning are low at a given temperature. Sta-ting the matter in slightly different language, the material has a high ignition ten'iperature and a low burning rate.

The high ignition temperatures and the low burning rates have rendered these fuels unsuitable for use in certain industries. For example, coal-tar coke has been tested for use in the manufacture of carbonic acid (carbon dioxid), and found. unsatisfactory because of its high ignition temperature. Again, as a covering for molten lead in the steel treating lead pot, gas coke, coal-tar coke and petroleum coke are not suitable When used alone, especially in the lower temperature-range of the lead bath, though their relatively high density and low ash content are desirable characteristics. A coke igniting at a lOW temperature and burning more rapidly at the temperature of the lead bath offers many practical advantages in this art. Such a carbon as WOOCl charcoal burns at a sufiiciently rapid rate for use as a lead pot covering and is in common use, but has a low density and a high ash as compared with coke.

Among the substances which We have found suitable to lower the ignition tem perature as Well as increase the burning rate of carbonized carbonaceous materials may be mentioned the following: metallic lead;

Application filed August 11, 1923. Serial No. 656,914.

lead carbonate; lead acetate; lead sulfide; lead iodide; lead cresylate and other organic lead compounds; thallium compounds; copper oxid; barium dioxid and organic .compounds .of these metals easily reducible to the oxid state. It is apparent from the above that the oXid of the metal may itself be used, or that either organic or inorganic metal compounds, Which easily pass into the oxid state When heated by a straight reduction or oxidation reaction or a combination thereof may be used. Some of the metal oxids appear to give better results than others and this Will later be referred toin more detail. The best results have so far been attainedby the use of the cresylate or the oNids of lead, and the manufacture of our low igniting carbon composition and the ignition temperatures of the same will be set forthin connection With the use of the oxide of lead.

To make a coke product the following methods of manufacture may be used: (1) incorporate lead or any of the oxids of lead with pitch andcarbonize or coke the mire tare; incorporate ,lead carbonate,-lead acetate or any material which When heated Willgive the oiiid, With pitch and carbonize it; cause the oxid to adhereto the surface of the coke by any well-known method; and (at) dissolve a lead compound such as lead cresylate, in coal-tar or pitch and distill the tar or pitch to coke. By method (4) We areable to molecularly disperse the lead throughout the coke structure thus obtaining maximum catalytic effect. To make a charcoal product'the following methods of manufacture may be used: (1) rub lead oXid into the pores of the charcoal; (2) saturate the charcoal with asuspension of a lead compound which on heating Will give the oxid, and then heat to change the compound to an oxid. Forexample, lead acetate in Water 01 lead cresylate in organic solvents may be employed.

It will be understood of course that the proper proportion of materials Will be employed in making up the mass in bulk; thus, for producing several tons of coal-tar coke containing lead, ive introduce into the still containing, say 42,000 pounds of coal tar, 160 pounds of lead oxide (e. g. PbO litharge). The lead oxide becomes dispersed in the tar upon heating and dissolves, thus disor solution tributing itself throughout the tar in molecular subdivision. The tar is then distilled in the usual manner until all the oils and" distilling off the volatile oils and obtaining coke in the still as a residue.

In U. S. Patent No. 1,230,782 there is set forth the production of coke resulting from the complete distillation of coal tar. This coke is characterized by the fact that it is sponge-like in appearance, amorphous, noncrystalline, dry, and when burned leaves a residue approximating two per cent composed of non-combustible matter and mineral ash. The coke is also characterized by presenting when fractured a steel-gray surface upon the area of'fracture, with a brilliant or glossy surface upon the walls of the'depressions, pockets, or recesses appearing therein.

As hitherto pointed out, there is a field of great utility for a relatively dense, low ash, carbonaceous material igniting and burning at a low temperature, for example, at the temperature at which wood charcoal ignites and continues to burn, the temperatures of burning of course varying in some cases, through a certain range. The coal-tar coke referred to has a satisfactory density and has, relatively speaking, a lOW ash content. N hen certain metals or metal compounds are added thereto, its ignition temperature is so depressed and the burning rate so in creased that the resulting composition meets the requirements above set forth and makes possible the use of the low-ash coal-tar colre in various industries. For example, we find that such coal-tar coke containing one per cent of litharge is as eliicient as wood charcoal and preferable from an ash'standpoint. In one particular sample of coal-tar coke used, an analysis showed an ash-content of 1.3 per cent. \Vood charcoal usually contains from 8 to 10 per cent of ash.

If lead compounds are incorporated with coal before coking the colre so formed ignites at much lower temperatures than ordinary gas coke.

The following tabl indicates the depression of the ignition temperature when oxids of lead are added to low ash coa1tar coke and to wood-charcoal.

The ignition temperature is taken as the temperature at which appreciable combustion begins. The glow point is an indicator of the ignition temperature due to the fact Test No. 1.

Air passed over 10 grams of the material. at the rate of 1.3 liters per hour, in a 1 glass tube heated in an electric furnace.

Ignition TGIHDOP Material. i tempera: zltlllc (le- Lure. presslon. 1 C. 1. Coal-tar coke 050 2. Coal-tar coke and 2% Pinon... 5.30 100 3. Coal-tar COlIO and 25% wood charcoal and .2 r 30.; 470 180 4. Coal-tar coke and 6% PbJO 160 Test No. II.

Air passed over material at the rate of 1.3 liters per hour. Same apparatus.

Temper- Material. g g attire dc p 1 prcsslon.

0 0. C. Wood charcoal 450 Wood charcoal and 2% PhD 310 140 Test1V0. [11. Air passed over material at rate of 3 3 liters per hour. Same apparatus.

' Tom er- Material. 33? ature dcp pression.

0. 0. ,1. Coal-tar coke 5S5 2. Coal-tar coke and 2% Pb30 405 180 3. Coal-tar coke and PbO. 400 185 4. Coal'tar coke and PbO (resulting from lead cresylate dccompositio 330 255 5. Coal-tar coke and 5% PbO (resulting from decomposition of lead cresylate dissolved l in tar) 395 l 190 On cooling the samples of Test No. III, material No. 1, coke alone, ceased to glow (burn) at 500 C., while material No. 3 P00) ceased to glow (burn) at 260 C. Thus, PbO lowered the ignition temperature 185 C. and the temperature range through which the coke continued to burn approximately 240 C.

To show the decided difierence between the lead impregnated coke and the usual coal tar coke, one piece of each was heated in the air to glowing. On removing the source of heat, the coal tar coke immediately blackened and cooled while the lead impregnated coke continued to glow, in a manner similar to is not satisfactory because of its low rate of l'iurning at this temperature.

Fifty (50) percent PM) in coal tar coke gives a material which may be lighted with a match and will sparkle and glow brightly when blown with air, whereas ordinary coal tar coke can notbe so lighted and when lighted at higher temperature is extinguished by a current of air.

As stated, other metals or metal compounds may be used. For example, the presence of copper oxid in coal-tar coke has an effect similar to the action of the compounds of lead but not to the same extent. Fifty percent of copper oXid is necessary to approximate the results obtained with onchalf to one percent of lead oxid. Using copper OTiid in amounts ranging from live to ten percent only a slight depression in the ionition point is obtained. lVe have also found that 50% barium dioxid and 50% nickel oxid are effective to depress the igni-c tion point but their activity is decidedly lower than either that of the oxide of lead or copper.

in the specification the percentages of oxids added are based on the combined weight of the coal-tar coke and the oXid. For example, two percent lEb O indicates that the mix cOlDPl'iSGS 98 parts of coke and parts of oxid, by weight.

Due to the great activity of small percentages of the lead compounds, also because of the activity of compounds not containing oxygen, the effect is clearly a catalytic one. In the specification, then, we use the term catalyst to denote asubstance which has the power of accelerating the combustion of carbon or carbonaceous material in the manner herein described in such a way as to lower the ignition ten'iperature and increase the rate of burning at a given temperature.

Vi e claim:

1. A new article of manufacture having a relatively low ignition temperature and a relatively high burning rate comprising a carbonized material and a substance containing a metal which catalyzes the combustion.

A new article of manufacture having a relatively low ignition temperature and a relatively high burning rate, comprising a. carbonized material and a metal compound which serves as a catalyst for the combustion.

3. A new article of manufacture having a relatively low ignition temperature and a relatively high burning rate comprising a.

carbonized material and a metal oxid catalyst. i

4. A'newarticle of manufacture having a relatively low ignition temperature and a relatively high burning rate comprising a carbonized material and from 0.1 to 50 per cent of a metal oxid catalyst.

A new article of manufacture having a relatively low ignition temperature and a relatively high burning rate, comprising a carbonized material and an oXid of lead.

(3. A new article of manufacture having a relatively low ignition.temperature and a' relatively high burning rate comprising a carbonized material and from 0.1 to 50 per cent of an oxid of lead. i

7. A new article of manufacture having relatively low ignition temperature and relatively high burning rate comprising carbonized material and a substance containing lead.

8. A new article of manufacture haying a relatively low ignition temperature and a relativcl 1 high burning rate comprising coaltar coke and a suliistance containing a metal which acts as a catalyst for the carbon combustion.

9. A new article of manufacture having a relatively low ignition temperature and a relatively high burning rate comprising coal-tar coke and a metal compound as a combustion catalyst.

10. A new article of manufacture having a relatively low ignition temperature and a relatively high burning rate, comprising coal-tar coke and a metal OXlCl catalyst.

11. A new article of manufacture having a. relatively low ignition temperature and a relatively high burning rate comprising coal-tar coke and from 0.1 to 50 per cent of a metal oxid serving as a catalyst to acceler ate the combustion.

12. A new article of manufacture having a relatively low ignition temperature and a relatively high burning rate comp ising coal-tar coke and an oxid of lead.

13. A new article of manufacture having. a relatively low ignition temperature and a relatively high burning rate comprising coal-tar coke and from 0.1 to 50 per cent of an oxid of lead.

14. A new article of manufacture having a relatively low ignition temperature and a relatively high burning rate comprising coal-tar coke and a substance containing lead.

15. A new article of manufacture comprising coke produced as the result of the complete distillation of coal-tar, said coke being characterized by the fact that it is sponge-like in structure, and non-crystalline, is dry, and when burned leaves a residue ap proximating two per cent composed of non; combustible matter and mineral ash; and a substance containing a metal acting as a combustion catalyst.

16. A new article of manufacture comprising coke produced as the result of the complete distillation of coal-tar, said coke being characterized by the fact that it is sponge-like in appearance, and non-crystalline is dry, and when burned leaves a residue approximating two percent composed of non-combustible matter and mineral ash; and a metal compound which catalyzes the combustion reaction.

17. A new article of manufacture comprising coke produced as the result of the complete distillation of coal-tar, said coke being c aracterized by the fact that it is spongelilre in appearance, and non-crystalline, is dry, and when burned leaves a residue approximating two per cent-composed of noncombustible matter and mineral ash; and a metal oxid combustion catalyst.

18. A new article of manufacture coinprising coke produced as the result of the complete distillation of coal-tar, said coke being characterized by the fact that it is sponge-like in appearance, and non-cretalline, is dry, and when burned leaves a residue approximating two per cent composed of noncombustible matter and mineral ash; and from 0.1 to per cent of a metal oxid catalyst.

19. A new article of manufacture comprising coke produced as the result of the complete distillation of coal-tar, said coke being characterized by the fact that it is sponge-like in appearance, and non-crystalline, is dry, and when burned leaves a residue approximating two per cent composed of non-combustible matter and mineral ash;

I andan oxid of lead.

20. A new article of manufacture comprising coke produced as the result of the complete distillation of coal-tar, said coke being characterized by the fact that it is sponge-like in appearance, and non-crystalline, is dry, and when burned leaves a residue approximating two percent, composed of non-combustible matter and mineral ash; and from 0.1 to 50 per cent of an oxid of lead.

21. A new article of manufacture comprising coke produced as the result of the complete distillation of coal-tar, said coke being characterized by the fact that it is sponge-like in appearance, amorphous, and noncrystalline, is dry, and when burned leaves a residue approximating two per cent composed of non-combustible matter and mineral ash and a substance containing lead.

22. The process of treating carbonized material to depress its ignition temperature and increase its burning rate comprising incorporating therewith a substance containing a metal which serves as a catalyst for the combustion.

28. The process of treating carbonaceous material to depress the ignition temperature and increase the burning rate of its carbonized product comprising adding thereto a metal compound as a catalyst forfthe combustion, and carbonizing the mixture.

24-. The process of treating carbonized material to depress its ignition and increase its burning rate comprising adding thereto a metal oxid which serves to catalyze the combustion reaction.

25. The process of treating carbonized material to depress its ignition temperature and increase its burning rate comprising incorporating therewith an oxid of lead.

In testimony whereof we have signed our names to this specification.

IRA H. DERBY. CARLETON B. EDWARDS. 

